EGFR Exon 20 Lung Cancer: First-Line Sunvozertinib Outperformed Chemotherapy

Is First-Line Treatment Changing in Lung Cancer with EGFR Exon 20 Insertions?

EGFR Exon 20 Insertions: A Different Challenge from Classic EGFR Mutations

EGFR exon 20 insertion mutations are a less common but clinically very challenging subgroup of EGFR-mutated NSCLC. These mutations arise from small genetic fragments inserted into the exon 20 region of the EGFR gene. The resulting structural change makes it harder for classic EGFR inhibitors to bind. Older-generation EGFR TKIs, which are very effective in classic EGFR mutations such as exon 19 deletions or L858R, therefore generally do not show sufficient efficacy in exon 20 insertions.

This patient group was historically treated with chemotherapy. In recent years, EGFR/MET-targeted antibodies such as amivantamab and more selective oral EGFR exon 20 inhibitors such as sunvozertinib have begun to fill this gap. In July 2025, sunvozertinib received accelerated approval from the US FDA for metastatic NSCLC with EGFR exon 20 insertions that had progressed after platinum-based chemotherapy. WU-KONG28 is testing this drug earlier, in the first line.

First-Line Oral Targeted Treatment Versus Platinum-Pemetrexed Chemotherapy

WU-KONG28 is a randomized, multinational, open-label phase 3 study conducted in treatment-naive patients with advanced NSCLC with EGFR exon 20 insertions. The study included patients with locally advanced or metastatic nonsquamous NSCLC, carrying an EGFR exon 20 insertion mutation, who had not previously received systemic treatment for advanced disease.

Patients were randomized 1:1 to two arms. In the sunvozertinib arm, patients received 300 mg orally, once daily of sunvozertinib. The control arm received carboplatin + pemetrexed chemotherapy; eligible patients continued pemetrexed maintenance. When disease progression in the chemotherapy arm was confirmed by BICR, crossover to sunvozertinib was permitted.

PFS: 10,3 Months Versus 7,5 Months

The primary endpoint of WU-KONG28 was met. According to BICR assessment, median progression-free survival in the sunvozertinib arm was 10,3 months, and in the chemotherapy arm it was 7,5 months . The hazard ratio was reported as 0,65, with a 95% confidence interval of 0,50–0,85 and a P value of 0,0008 .

This result shows that sunvozertinib reduced the risk of disease progression or death compared with chemotherapy by approximately 35% in relative terms . The 12-month PFS rate with sunvozertinib was %46,1, and with chemotherapy it was %26,7; the 18-month PFS rates were, respectively, %33,2 and %17,1 .

Response Rate Almost Doubled: 58,9% Versus 31,1%

Sunvozertinib not only delayed disease progression but also increased the tumor shrinkage rate. The confirmed objective response rate in the sunvozertinib arm was %58,9, and in the chemotherapy arm it was %31,1 . Duration of response also favored sunvozertinib: the median duration of response was 11,2 months, compared with 7,1 months reported in the chemotherapy arm.

PFS2 Also Favors Sunvozertinib: The Initial Treatment Sequence May Matter

Second progression-free survival, or PFS2, in WU-KONG28 was also reported to favor sunvozertinib. Median PFS2 in the sunvozertinib arm was 21,7 months, and in the chemotherapy arm it was 15,5 months ; the HR was reported as 0,70 and the P value as 0,0111 .

EGFR-Class Adverse Effects and CPK Elevation Stand Out

Sunvozertinib's safety profile was reported to be consistent with previous studies and generally manageable. According to the OncLive summary, the rate of drug-related, grade 3 or higher treatment-related adverse events in the sunvozertinib arm was %61 . The rate of adverse events leading to treatment discontinuation was reported as %7,4 , and no treatment-related fatal adverse events were reported.

The main adverse effects requiring attention with sunvozertinib, consistent with the EGFR TKI class, are gastrointestinal adverse effects, skin rash, mucosal effects, ocular toxicity, and the rare risk of interstitial lung disease/pneumonitis. CPK elevation is also among the laboratory findings that require monitoring with this agent.

The New Question After PAPILLON: Antibody + Chemotherapy or an Oral TKI?

First-line treatment of advanced NSCLC with EGFR exon 20 insertions no longer consists of chemotherapy alone. The PAPILLON study showed that amivantamab + chemotherapy significantly prolonged PFS compared with chemotherapy. With this study, amivantamab + carboplatin/pemetrexed became an important first-line option in many guidelines and in practice.

WU-KONG28 offers a different approach: single-agent oral targeted treatment instead of an intravenous antibody + chemotherapy combination. Because these two approaches have not been compared directly, it is not correct to say which is better. However, in clinical practice these two datasets show that molecularly targeted first-line options are now gaining strength in patients with EGFR exon 20 insertions.

The Case for Using Targeted Treatment Earlier Is Strengthening

The most important clinical message of WU-KONG28 is that targeted treatment in advanced NSCLC with EGFR exon 20 insertions may no longer be confined to the post-platinum setting. Sunvozertinib demonstrating superiority in PFS and ORR over chemotherapy in the first line strengthens the idea of starting treatment with a molecularly targeted approach in patients carrying this mutation.

In practice, however, the decision will depend on several factors: country-specific approval and reimbursement status, access to amivantamab + chemotherapy, the patient's suitability for intravenous treatment, preferences for oral treatment, the presence of brain metastases, the exon 20 insertion subtype, adverse effect profile, and overall performance status.

Hope for an Oral Targeted Treatment Alternative to Chemotherapy

Earlier Use of Targeted Treatment Is Gaining Strength in EGFR Exon 20 Patients

How Will Sunvozertinib's True Place in the First Line Be Determined?

A Chemotherapy-Free First-Line Era Is Approaching in Lung Cancer with EGFR Exon 20 Insertions

The WU-KONG28 study showed that first-line sunvozertinib provides better disease control than platinum-pemetrexed chemotherapy in advanced NSCLC with EGFR exon 20 insertions. Median PFS was reported as 10,3 months versus 7,5 months, HR 0,65, and P=0,0008. The objective response rate also favored sunvozertinib, at 58,9% versus 31,1%.

This result suggests that targeted treatment can now be used earlier in the EGFR exon 20 patient group, which remained dependent on chemotherapy for years. In particular, the option of single-agent oral targeted treatment may offer an important advantage in patient comfort and treatment practice.

However, overall survival data are not yet mature, and the high crossover rate in the chemotherapy arm will complicate OS interpretation. Sunvozertinib's ultimate place in the first line will therefore become clear together with mature survival data, CNS results, resistance biology, clinical positioning relative to amivantamab + chemotherapy, and country-specific approval/access conditions. Nevertheless, this study brings the future of molecularly targeted treatment in lung cancer with EGFR exon 20 insertions substantially closer.